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Mangroves among the most carbon-rich forest in the tropics

  • Washington Department of Natural Resources & University of Washington
  • Center for International Forestry Research Bogor Indonesia & Department of Geophysics and Meteorology IPB University Bogor
PUBLISHED ONLINE: 3 APRIL 2011 | DOI: 10.1038/NGEO1123
Mangroves among the most carbon-rich forests in
the tropics
Daniel C. Donato1*, J. Boone Kauffman2, Daniel Murdiyarso3, Sofyan Kurnianto3, Melanie Stidham4
and Markku Kanninen5
Mangrove forests occur along ocean coastlines throughout the
tropics, and support numerous ecosystem services, including
fisheries production and nutrient cycling. However, the areal
extent of mangrove forests has declined by 30–50% over the
past half century as a result of coastal development, aqua-
culture expansion and over-harvesting1–4. Carbon emissions
resulting from mangrove loss are uncertain, owing in part to
a lack of broad-scale data on the amount of carbon stored
in these ecosystems, particularly below ground5. Here, we
quantified whole-ecosystem carbon storage by measuring tree
and dead wood biomass, soil carbon content, and soil depth in
25 mangrove forests across a broad area of the Indo-Pacific
region—spanning 30of latitude and 73of longitude—where
mangrove area and diversity are greatest4,6. These data indi-
cate that mangroves are among the most carbon-rich forests
in the tropics, containing on average 1,023 Mg carbon per
hectare. Organic-rich soils ranged from 0.5m to more than 3 m
in depth and accounted for 49–98% of carbon storage in these
systems. Combining our data with other published information,
we estimate that mangrove deforestation generates emissions
of 0.02–0.12 Pg carbon per year—as much as around 10% of
emissions from deforestation globally, despite accounting for
just 0.7% of tropical forest area6,7.
Deforestation and land-use change currently account for 8–20%
of global anthropogenic carbon dioxide (CO2) emissions, second
only to fossil fuel combustion7,8. Recent international climate
agreements highlight Reduced Emissions from Deforestation and
Degradation (REDD+) as a key and relatively cost-effective option
for mitigating climate change; the strategy aims to maintain
terrestrial carbon (C) stores through financial incentives for forest
conservation (for example, carbon credits). REDD+and similar
programs require rigorous monitoring of C pools and emissions8,9,
underscoring the importance of robust C storage estimates for
various forest types, particularly those with a combination of high
C density and widespread land-use change10.
Tropical wetland forests (for example, peatlands) contain
organic soils up to several metres deep and are among the largest
organic C reserves in the terrestrial biosphere11–13. Peatlands’
disproportionate importance in the link between land use and
climate change has received significant attention since 1997, when
peat fires associated with land clearing in Indonesia increased
atmospheric CO2enrichment by 13–40% over global annual
fossil fuel emissions11. This importance has prompted calls to
specifically address tropical peatlands in international climate
change mitigation strategies7,13.
1USDA Forest Service, Pacific Southwest Research Station, 60 Nowelo St., Hilo, Hawaii 96720, USA, 2USDA Forest Service, Northern Research Station, 271
Mast Rd., Durham, New Hampshire 03824, USA, 3Center for International Forestry Research (CIFOR), PO Box 0113 BOCBD, Bogor 16000, Indonesia,
4USDA Forest Service, International Programs, 1099 14th street NW, Suite 5500W, Washington, District of Columbia 20005, USA, 5Viikki Tropical
Resources Institute (VITRI), University of Helsinki, PO Box 27, FIN-00014, Finland. *
Overlooked in this discussion are mangrove forests, which occur
along the coasts of most major oceans in 118 countries, adding
30–35% to the global area of tropical wetland forest over peat
swamps alone4,6,12. Renowned for an array of ecosystem services,
including fisheries and fibre production, sediment regulation, and
storm/tsunami protection2–4, mangroves are nevertheless declining
rapidly as a result of land clearing, aquaculture expansion,
overharvesting, and development2–6. A 30–50% areal decline over
the past half-century1,3 has prompted estimates that mangroves
may functionally disappear in as little as 100 years (refs 1,2). Rapid
twenty-first century sea-level rise has also been cited as a primary
threat to mangroves14, which have responded to past sea-level
changes by migrating landward or upward15.
Although mangroves are well known for high C assimilation
and flux rates16–22, data are surprisingly lacking on whole-ecosystem
carbon storage—the amount which stands to be released with
land-use conversion. Limited components of C storage have been
reported, most notably tree biomass17,18, but evidence of deep
organic-rich soils22–25 suggests these estimates miss the vast majority
of total ecosystem carbon. Mangrove soils consist of a variably
thick, tidally submerged suboxic layer (variously called ‘peat’ or
‘muck’) supporting anaerobic decomposition pathways and having
moderate to high C concentration16,20,21. Below-ground C storage
in mangrove soils is difficult to quantify5,21 and is not a simple
function of measured flux rates—it also integrates thousands of
years of variable deposition, transformation, and erosion dynamics
associated with fluctuating sea levels and episodic disturbances15.
No studies so far have integrated the necessary measurements for
total mangrove C storage across broad geographic domains.
In this study we quantified whole-ecosystem C storage in
mangroves across a broad tract of the Indo-Pacific region, the
geographic core of mangrove area (40% globally) and diversity4,6.
Study sites comprised wide variation in stand composition
and stature (Fig. 1, Supplementary Table S1), spanning 30
of latitude (8S–22N), 73of longitude (90–163E), and
including eastern Micronesia (Kosrae); western Micronesia
(Yap and Palau); Sulawesi, Java, Borneo (Indonesia); and the
Sundarbans (Ganges-Brahmaputra Delta, Bangladesh). Along
transects running inland from the seaward edge, we combined
established biometric techniques with soil coring to assess variations
in above- and below-ground C pools as a function of distance
from the seaward edge in two major geomorphic settings:
estuarine/river-delta and oceanic/fringe. Estuarine mangroves
(n=10) were situated on large alluvial deltas, often with a
protected lagoon; oceanic mangroves (n=15) were situated in
© 2011 Macmillan Publishers Limited. All rights reserved.
Figure 1 |Examples of Indo-Pacific mangroves. The sample included a
broad range of stand stature, composition, and soil depth. a, Exemplary
large-stature, high-density mangrove dominated by Bruguiera, Borneo,
Indonesia (canopy height >15 m, canopy closure >90%, soil depth >3 m).
b, Exemplary small-stature, low-density mangrove dominated by
Rhizophora, Sulawesi, Indonesia (canopy height <4m, canopy closure
<60%, soil depth 0.35–0.78m). Both estuarine and oceanic mangroves
can exhibit both conditions (see Supplementary Table S1).
marine-edge settings, often the coasts of islands with fringing
coral reefs. Seaward distance and geomorphic setting may
influence C dynamics through differences in tidal flushing and
relative importance of allochthonous (river sediment) versus
autochthonous (in situ litter and root production) controls on soil
C accumulation5,16.
We found that mangroves are among the most C-dense forests
in the tropics (sample-wide mean: 1,023 Mg C ha1±88 s.e.m.),
and exceptionally high compared to mean C storage of the
world’s major forest domains (Fig. 2). Estuarine sites contained
a mean of 1,074 Mg C ha1(±171 s.e.m.); oceanic sites contained
990 ±96 Mg C ha1. Above-ground C pools were sizeable (mean
159 Mg C ha1, maximum 435 Mg C ha1), but below-ground
storage in soils dominated, accounting for 71–98% and 49–90%
of total storage in estuarine and oceanic sites, respectively (Figs 2
and 3). Below-ground C storage was positively but weakly
correlated to above-ground storage (R2=0.21 and 0.50 in estuarine
and oceanic sites, respectively). Although soil C pools increased
slightly with distance from the seaward edge in oceanic sites
(because of increasing soil depth), changes in both above- and
Boreal Temperate Tropical
Ecosystem C storage (Mg ha¬1)
Above-ground live + dead
Soils 0¬30 cm depth + roots
Soils below 30 cm depth
Figure 2 |Comparison of mangrove C storage (mean ±95% confidence
interval) with that of major global forest domains. Mean C storage by
domain was derived from ref. 9, including default values for tree, litter, dead
wood, root:shoot ratios, and soils, with the assumption that the top 30cm
of soil contains 50% of all C residing in soil9, except for boreal forests
(25%). Domain means are presented for context; however some forest
types within each contain substantially higher or lower C stores9,10. In
general, the top 30 cm of soil C are considered the most vulnerable to
land-use change9; however in suboxic peat/muck soils, drainage,
excavation, and oxidation may influence deeper layers29.
below-ground C storage over this distance gradient were highly
variable and not statistically significant (Fig. 3).
So far, quantification of below-ground C storage in man-
groves has been impeded by a lack of concurrent data on soil
carbon concentration, bulk density, and depth, and how these
vary spatially5,21. We found high C concentration (% dry mass)
throughout the top metre of the soil profile, with a decrease
below 1 m (Fig. 4a). Carbon concentration was lower in es-
tuarine (mean =7.9%) versus oceanic (mean =14.6%) sites.
Soil bulk density (BD) did not differ significantly by setting or
distance from the seaward edge (generally 0.35–0.55 g cm3),
but did increase with depth (Fig. 4b). Combining C concentra-
tion and BD yielded mean C densities of 0.038 g C cm3and
0.061 g C cm3in estuarine and oceanic soils, respectively. The
total depth of the peat/muck layer differed between estuarine
and oceanic sites (Fig. 4c) and was the main driver of varia-
tions in below-ground C storage (Fig. 3). Estuarine stands over-
lie deep alluvial sediment deposits, usually exceeding 3 m depth;
oceanic stands contained a distinct organic-rich layer overlying
hard coral sand or rock, with peat/muck thickness increasing
from a mean of 1.2 m (±0.2 s.e.m.) near the seaward edge to
1.7 m (±0.2 s.e.m.) 135 m inland (Fig. 4c). In terms of total
below-ground C storage, the shallower soil depth in oceanic man-
groves was compensated in part by higher soil organic C con-
centration (Fig. 4a,c).
These data indicate that high productivity and C flux rates
in mangroves16–22 are indeed accompanied by high C storage,
especially below ground. High per-hectare C storage coupled with
a pan-tropical distribution (total area 14 million ha; refs 4,6)
suggests mangroves are a globally important surface C reserve.
Although our sample is not intended to represent all mangrove
types (precluding simple scaling up), some constraints on global
storage can be derived by combining an uncertainty range from
our empirical data (5th to 95th percentile C storage values) with
additional global data on soil C concentration, depth, and standing
biomass16,17,21,23,24 (see Methods in Supplementary Information).
This approach yields an estimate of 4.0–20 Pg C globally. This
estimate will undoubtedly be refined, but suggests mangroves add
significantly to tropical wetland forest C storage (for example,
tropical peatlands: 82–92 Pg C; ref. 12).
© 2011 Macmillan Publishers Limited. All rights reserved.
Below-ground Above-ground
C storage (Mg ha¬1)
Below-ground Above-ground
C storage (Mg ha¬1)
0 10 35 60 85 110 135
Distance from seaward edge (m)
0 10 35 60 85 110 135
Distance from seaward edge (m)
Estuarine mangroves Oceanic mangroves
Down wood
Figure 3 |Above- and below-ground C pools in Indo-Pacific mangroves, assessed by distance from the seaward edge. a, Estuarine mangroves situated on
large alluvial deltas. b, Oceanic mangroves situated in marine edge environments—for example, island coasts. Below-ground C comprised 71–98% and
49–90% of ecosystem C in estuarine and oceanic sites, respectively. Overall carbon storage did not vary significantly with distance from the seaward edge
in either setting over the range sampled (P>0.10 for above-ground, below-ground, and total C storage by functional data analysis (FDA, see Methods);
95% CIs for rates-of-change all overlapped zero and were between 1.2 and 3.9 Mg C ha1per metre of distance from edge).
Carbon emissions from land-use change in mangroves are
not well understood. Our data suggest a potential for large
emissions owing to perturbation of large C stocks. The fate of
below-ground pools is particularly understudied, but available
evidence suggests that clearing, drainage, and/or conversion
to aquaculture—aside from affecting vegetation biomass—also
decreases mangrove soil C significantly16,22,26–28. In upland forests,
the top 30 cm of soil are generally considered the most susceptible
to land-use change9; however in wetland forests, drainage and
oxidation of formerly suboxic soils may also influence deeper
layers29. To provide some constraints on estimated emissions,
we used a similar uncertainty propagation technique, combining
our C storage values with other global data16,17 and applying
a range of assumptions regarding land-use effects on above-
and below-ground pools (see Supplementary Information). This
approach yields a plausible estimate of 112–392 Mg C released
per hectare cleared, depending in large part on how deeply soil
C is affected by different land uses. Coupled with published
ranges of mangrove deforestation rate (1–2%; refs 1,4) and global
area (13.7–15.2 million ha; refs 4,6), this estimate leads to global
emissions on the order of 0.02–0.12 Pg C yr1. This rate adds
significantly to oft-cited peatland emissions (0.30 Pg C yr1) and
global deforestation emissions (1.2 Pg C yr1; ref. 7) despite
accounting only for loss of standing stocks but not other known
mangrove-conversion influences, such as decreased C sequestration
rate, burial efficiency, and export to ocean16,18, nor increases in
normally-low methanogenesis in some disturbed soils16,27.
In addition to direct losses of forest cover, land-use activities
will also impact mangrove responses to sea-level rise14,15. Man-
groves have been remarkably persistent through rapid sea-level rises
(5–15 mm yr1) during the late Quaternary Period (0–18,000 yr bp)
because of (1) landward migration, and (2) autogenic changes
in soil-surface elevation through below-ground organic matter
production and/or sedimentation15. Under current climate trends,
sea level is projected to rise 18–79 cm from 1999–2099 (higher
if ice-sheet melting continues accelerating)8,30, implying a period-
averaged rate of 1.8–7.9 mm yr1, notwithstanding local varia-
tions and temporal nonlinearities. Although this rate is not unprece-
dented, it is unclear yet whether mangroves are currently keeping
pace with sea levels14,15. Anthropogenic influences could constrain
future resilience to sea-level rise through coastal developments
that impede inland migration (for example, roads, infrastructure),
upland land uses that alter sediment and water inputs (for example,
dams, land clearing), and mangrove degradation that reduces
below-ground productivity14. This synergy of land use and climate
change impacts presents additional uncertainties for the fate and
management of coastal C stores.
Critical uncertainties remain before estimates of mangrove C
storage and land-use emissions can be improved. Among these are
geographic variations in soil depth, a key but unknown parameter
in most regions5,21. Similarly, empirical data on land-use change
impacts on soil C is strongly lacking, especially for deep layers
(but see refs 26–28). Quantitative estimates are also needed of
the relative area occupied by estuarine/delta and oceanic/fringe
mangroves, which is not addressed in most analyses of mangrove
area4,6. Because these two systems store below-ground C differently,
improved spatial data will greatly refine estimates of global C storage
and emissions owing to disturbance.
Our data show that discussion of the key role of tropical wetland
forests in climate change could be broadened significantly to include
mangroves. Southeast Asian peatlands are currently being advanced
as an essential component of climate change mitigation strategies
such as REDD+(refs 7,13), and mangroves share many of the
same relevant characteristics: deep organic-rich soils, exceptionally
high C storage, and extensive deforestation/degradation resulting in
potentially large greenhouse gas emissions. The well-known ecosys-
tem services and geographic distribution of mangroves1–4 suggest
these mitigation strategies could be effective in providing ancillary
benefits as well as potential REDD+ opportunities in many tropical
countries. Because land use in mangroves affects not only standing
stocks but also ecosystem response to sea-level rise, maintaining
these C stores will require both in situ mitigation (for example,
reducing conversion rates) as well as facilitating adaptation to
rising seas. The latter challenge is largely unique to management
© 2011 Macmillan Publishers Limited. All rights reserved.
0 10 35 60 85 110 135
Distance from seaward edge (m)
0 10 35 60 85 110 135
Distance from seaward edge (m)
Organic C content (%)
10 20
Depth (m)
0 10 20 0 10 20 0 10 20 0 10 20 0 10 20
Estuarine Oceanic
Bulk density (g cm¬3)
0.3 0.6 0.3 0.6 0.3 0.6 0.3 0.6 0.3 0.6 0.3 0.6
Estuarine/oceanic combined
Soil depth (m)
Estuarine (88% >3 m)
Depth (m)
Soil depth (m)
Figure 4 |Soil properties determining below-ground carbon storage in
Indo-Pacific mangroves. a, Soil C concentration was greater in oceanic
(mean =14.6%) versus estuarine (mean =7.9%) sites (P=0.001), and
decreased with depth (P<0.0001; effect stronger in oceanic sites).
Change in C concentration with seaward distance was biologically
insignificant. b, Soil bulk density did not differ significantly with setting
(P=0.79); hence one line is shown combining both settings. Bulk density
increased with depth (P<0.0001) but not seaward distance (P=0.20),
and a distance*depth interaction term was not significant (P=0.47). c, Soil
depth increased with distance from the seaward edge in oceanic stands
(FDA result: P=0.002, 95% CI for rate-of-change =21–65 cm increase
per 100 m distance).
of coastal forests, calling for watershed-scale approaches, such
as landscape buffers for accommodating inland migration where
possible, maintenance of critical upstream sediment inputs, and
addressing degradation of mangrove productivity from pollution
and other exogenous impacts14,15.
We sampled 25 mangrove sites (n=10 estuarine, n=15 oceanic) across the
Indo-Pacific (8S–22N, 90–163E) using a transect starting from, and running
perpendicular to, the seaward edge. To maximize scope and representativeness,
we stratified the sample across a broad range of stand conditions—including
small-stature stands and shallow soils (<4 m canopy height, <10 cm mean tree
diameter, <0.5 m soil depth) to large-stature stands and deep soils (>15 m canopy
height, >20 cm mean tree diameter, soil depth >3m) (Supplementary Table S1).
These structural characteristics of forest stature and soil depth are primary
determinants of C storage, probably more so than environmental gradients or
geographic variation per se. Specific transect starts were determined randomly
a priori from aerial imagery, notwithstanding constraints of access and land
ownership. Within six circular sample plots spaced at 25-m intervals along each
transect, we measured standing tree and down wood (dead wood on forest floor)
biomass using standard biometric techniques (stem surveys, planar intercept
transects), then applying region-specific or common allometric equations and
C:biomass conversions for both above-ground and below-ground biomass. We
measured soil depths at three systematic locations in each plot using a graduated
aluminium probe (inference limit 3 m). We extracted a soil core from each plot
using a 6.4-cm open-face peat auger to minimize sample disturbance/compaction,
systematically divided the soil profile into depth intervals, and collected subsamples
from each interval. Subsamples were dried to constant mass and weighed for
bulk density determination, then analysed for C concentration using the dry
combustion method (induction furnace). Standard error in total ecosystem C
storage was computed by propagating standard errors of component pools. For
estuarine and oceanic sites separately, we analysed changes in soil depth and C
pools with distance from the seaward edge using functional data analysis (site-level
regressions for rate-of-change with distance, followed by a one-sample parametric
test on all rates-of-change for strength of positive or negative relationship). We
analysed spatial variations in soil C concentration and bulk density using linear
mixed-effects regression models, assessing fixed effects of depth, distance from
the seaward edge, and geomorphic setting, with a random effect of site to account
for within-site dependence. Ranges for global C storage and emission rates were
obtained using 5th percentile, mean, or 95th percentile estimates from this study
(which accounts for the possibility that biomass and soil C pools differ globally
from our mean values—higher or lower), with an adjusted soil C density based
on a recent global analysis16, combined with recently published low to high
estimates of global mangrove area and deforestation rate1,4,6. See full Methods in
Supplementary Information.
Received 30 September 2010; accepted 23 February 2011;
published online 3 April 2011
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We thank our many international partners and field personnel for assistance with
logistics and data collection: Kosrae Island Resource Management Authority; Yap
State Forestry; Orangutan Foundation International; Indonesian Directorate General
for Forest Protection and Nature Conservation; University of Manado and Bogor
Agricultural University, Indonesia; Bangladesh Forest Department; and KPSKSA
(Cilacap, Indonesia). We thank K. Gerow for statistical assistance, and R. Mackenzie,
C. Kryss and J. Bonham for assistance compiling site data. Funding was provided by
USDA Forest Service International Programs and the Australian Agency for International
Development (AusAID).
Author contributions
D.C.D. co-designed the study, collected field data, performed data analyses, and led the
writing of the paper. J.B.K. conceived and co-designed the study, and contributed to data
collection and writing. D.M. co-conceived the study, arranged for and contributed to data
collection, and contributed to writing. S.K. contributed to data collection, data analysis,
and writing. M.S. collected field data and contributed to writing. M.K. co-conceived the
study and contributed to writing.
Additional information
The authors declare no competing financial interests. Supplementary information
accompanies this paper on Reprints and permissions
information is available online at
Correspondence and requests for materials should be addressed to D.C.D.
© 2011 Macmillan Publishers Limited. All rights reserved.
... Mangroves grow on land that is periodically flooded with seawater and in anaerobic and acidic soils [1], and cover about 137,760 square kilometers in 118 countries in the tropics and subtropics [2]. They constitute a productive ecosystem, from providing economic and ecological value to protecting beaches from storm surges, erosion, and sedimentation [3] and serving as intense carbon sinks [4]. Mangrove forests are unique ecosystems of great social, economic, and vital importance. ...
... -1 , respectively, which did not record significant differences between them. While the leaf area decreased in the P 4 content of chlorophyll increased significantly in periods P 1 , P 2 , P 3 , and P 4 , which amounted to 49.68, 52.38, 52.7, and 52.1 µ -2 , respectively, which did not differ significantly between them, compared to plants when cultivated, which recorded 43.4 µ -2 . As for the average survival rate, the survival rate of seedlings amounted to 94% in the P 1 period, in the subsequent periods P 2 , P 3 and P 4 , a stable survival rate of seedlings amounted to 78% after the first planting of seedlings. ...
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A study was conducted to assess the growth indicators of mangroves Avicennia marina cultivated in the intertidal zone at the Khor Al-Zubair oil port site for the period from May 2020 to May 2021. The study showed high growth indicators. Recorded the highest averages indicators to the total height of the plant and the number of lateral branches were 113.4 cm and 30.4 branches. Plant ⁻¹ after 12 months from the date of planting in the site, while the highest average to indicators of the total number of leaves in the plant, the total leaf area, and the total leaf content of chlorophyll reached 176 leaves.plant ⁻¹ , 3511 cm ² .plant ⁻¹ , and 52.7 μ ⁻² were after 9 months of cultivation in the field, respectively. While the plants achieved survival rates of 78% at the end of the experiment. The results were compared according to the Least Significant Difference (L.S.D.) test at a probability level of 0.05.
... R. mangle presents the Introduction Coastal wetlands are important in global carbon dynamics, due to their high capacity to store carbon, now known as blue carbon (Bridgham et al., 2006). Mangroves are recognized as the wetlands with the most significant capacity to store carbon, which exceeds two to three times the amounts stored by terrestrial systems (Donato et al., 2011;Adame et al., 2013). This ability to store carbon is due to their high productivity and the low rates of organic matter decomposition, which tends to occur under total or partial flooding conditions (Adame et al., 2015). ...
... Mangroves store considerable amounts of carbon, mainly in the soil, product of the accumulation and burial of sediments, and the constant production of organic matter (Donato et al., 2011). In principle, the degradation of organic remains is associated not only with the reduction of carbon sequestration but also with the release into the atmosphere of large amounts of CO2 and of methane (CH4) as a product of respiration during the decomposition of organic matter in anoxic soils (Kauffman et al., 2012). ...
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Mangroves are recognized as the wetlands with the most significant capacity to store carbon, this ability to store carbon is due to their high productivity and the low rates of organic matter decomposition. The study area is one of the Intensive Carbon Monitoring Sites (SMIC, initials in Spanish) in Mexico. In the southern coast of the Mexican Pacific, in the La Encrucijada Biosphere Reserve (REBIEN). The SMIC has an extension of 1x1 km. In this area there are eight conglomerates. Each conglomerate contains four circular-shaped secondary units of 400 m2. The inventory includes trees ≥ 2.5 cm of DBH (Diameter at breast height). Tree species, DBH, height, canopy diameter, the basal area and tree density. Tree biomass was quantified, and the carbon store was determined using the biomass-to-carbon conversion factor of 0.48. The carbon in standing dead trees was estimated using the methodology of Kauffman et al. (2012). The environmental parameters quantified: interstitial salinity, pH, temperature and flood level. Results R. mangle is the dominant species, conglomerate 2 presented the highest tree density and conglomerate 4 the lowest. Conglomerates 8 and 4 had the highest averages for DBH, basal area, height, and crown area, in contrast, the conglomerates 1, 5, and 2, had the lowest averages. In the study area, the fall of trees was the factor that most affected the aboveground (aerial) carbon content, which increased 6.91 and 3% respectively during the second and third year of monitoring. Natural mortality increased and affected mostly young trees 2.5 to 10 cm tall. Wood extraction remained constant during the three years of study. During the three years of study, conglomerate 6 presented the highest biomass averages with 210.4 Mgha-1 and carbon stores of 101.0 MgCha-1; in contrast, conglomerate 5 registered the lowest average with 124.9 Mgha-1 and 60.0 MgCha-1 . R. mangle presents the biggest store of carbon with 60.4 MgCha-1. This mangrove system registered an increase in natural mortality during the study period, which could be the result of the massive amounts of sediment the river has been carrying after the passage of Hurricane “Stan” in 2005.
... In restored mangrove forests, soil carbon sequestration improves with age 49 . Previous studies reported that mature mangrove forests accumulated far more carbon than younger forests 4,45 . The SOC density of 4-yrs restored mangrove forest is 2.99-11.41 ...
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Blue carbon in mangrove ecosystems contributes significantly to the global carbon cycle. However, large uncertainties maintain in the soil organic carbon (SOC) storage throughout the tide-induced salinity and alkalinity transect in the mangrove restoration region in Southern China. Total 125 soil samples were obtained to detect the SOC content and physicochemical properties. The mean SOC content of each layer ranged from 6.82 to 7.86 g kg⁻¹, while the SOC density ranged from 2.99 to 11.41 kg m⁻², increasing with soil depths. From different land covers in the study region, the SOC content varied from 4.63 to 9.71 g kg⁻¹, increasing across the salinity and alkalinity transect, while the SOC density fluctuated from 3.01 kg m⁻² in mudflats to 10.05 kg m⁻² in mangrove forests. SOC concentration was favorably linked with total nitrogen (r = 0.95), and total phosphorus (r = 0.74), and negatively correlated with Cl⁻ (r = − 0.95), electrical conductivity (r = − 0.24), and total dissolved solids (r = − 0.08). There were significant logarithmic relationships between SOC content and the concentrations of clay (r = 0.76), fine silt (r = 0.81), medium silt (r = − 0.82), and coarse silt (r = − 0.78). The spatial patterns of SOC concentration were notably affected by soil texture, physicochemical properties, and land-cover type, providing essential reference for future investigations of blue carbon budget in restored mangrove forests.
... Currently, the area of mangrove ecosystems in Indonesia has decreased by about 30-50% with a deforestation rate of 52.000 ha yr -1 [2]. Mangrove deforestation is identified as caused by land use change, pond development, agriculture, industry, abrasion, and excessive logging [3,4]. ...
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Mangrove ecosystem Segara Anakan Lagoon (SAL), is the largest mangrove ecosystem in Java that is occupied by various types of mangroves. Several studies have shown the deforestation of mangrove in SAL which caused the decrease of mangrove biodiversity and species density. This study aims to obtain updated information on the distribution and density of two mangrove species found in SAL that are listed in the IUCN, which are Ceriops decandra (Threatened) and Merope angulata (Least Concerned). This research was conducted with the stages of literature study and analysis of satellite imagery using Sentinel 2 and the NDVI equation to obtain the change of mangrove cover and density. The literature study found that C. decandra was mostly distributed in the eastern and central sites of the Lagoon, while M. angulata was distributed in the center site. According to the spatial analysis, the density of Ceriops decandra was found >0,5 while Merope angulata is distributed in the center site with a medium density categorized. The degradation of the mangrove ecosystem in 2023 was estimated to be 10.493,64 ha. The information provided in this study is expected to improve conservation and protection actions for the sustainability of the threatened mangroves species in SAL.
... Sutaryo (2009) Komiyama et al. (2008) yang melaporkan bahwa ekosistem mangrove memiliki peranan yang penting dalam mengurangi efek gas rumah kaca sebagai mitigasi perubahan iklim karena mampu mereduksi CO 2 melalui mekanisme "sekuestrasi", yaitu penyerapan karbon dari atmosfer dan penyimpanannya dalam bentuk biomassa. Tiap hektar ekosistem mangrove dapat menyimpan karbon empat kali lebih banyak dibanding dengan ekosistem lainnya (Daniel et al. 2011 ...
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Ekosistem mangrove memiliki kemampuan menyerap CO2 lebih tinggi dibandingkan dengan vegetasi tumbuhan lainnya. Namun upaya pengelolaannya sebagai kawasan penyimpan stok karbon masih belum maksimal. Kota Makassar memiliki Sungai Tallo yang sepanjang bantarannya ditumbuhi oleh vegetasi mangrove dan sangat potensial untuk dikelola sebagai ruang terbuka hijau. Hasil pengamatan menunjukkan bahwa Sungai Tallo terletak tepat di tengah kota Makassar dan sepanjang bantaran sungai didominasi oleh spesies Nypa fruticans dengan jumlah 18.514 pohon dan kerapatan 4.256 pohon/ha, menyimpan karbon sebesar 21,82 ton C/ha, menyerap 80,02 ton CO2/ha. Spesies dominan kedua adalah Rhizophora mucronata dengan jumlah 8.492 pohon dan kerapatan 2.352 pohon/ha, menyimpan karbon sebesar 19,94 ton C/ha, menyerap 73,13 ton CO2/ha. Spesies dominan ketiga yaitu Avicennia alba dengan jumlah 2.421 pohon dan kerapatan 3.228 pohon/ha, menyimpan karbon sebesar 53,96 ton C/ha, menyerap 197,87 ton CO2/ha. Nilai kerapatan dan kemampuan serapan mangrove tersebut sangat sesuai untuk dikelola pada ruang terbuka hijau penyuplai udara segar dan penyerap CO2.Stock Estimation and Carbon Absorption of Mangrove in Tallo River, MakassarAbstractThe mangrove ecosystem has a higher ability of CO2 absorption than other vegetations. However, the effort to establish the mangrove to be a carbon stock area has not been achieved. Makassar has Tallo River, covered with mangrove vegetation along its riverbank, which is potent to be managed as a green open space. The observations indicated that Tallo River was located in the center part of Makassar city and was dominated by Nypa fruticans along the riverbanks in 18,514 trees and a density of 4,256 trees/ha, stored carbon of 21.82 tons C/ha, and absorbs 80.02 tons CO2/ha. Rhizophora mucronata was the second dominant species in 8.492 trees and density of 2,352 trees/ha, stored carbon of 19.94 tons C/ha, and absorbs 73.13 tons CO2/ha. The third dominant species was Avicennia alba in 2,421 trees and density of 3,228 trees/ha, stored carbon of 263.85 tons C/ha, and absorbs 197.89 tons CO2/ha. The density and ability to absorb values of the mangrove is highly suitable to be managed for a green open space to supply fresh air and CO2.
... Mangrove ecosystems are restricted to the intertidal area of estuaries, creeks, sheltered bays and coastlines in tropical and sub-tropical areas worldwide (Mukherjee et al., 2014;Tomlinson, 2016). These tidal forests provide an array of ecosystem services such as the provision of nursery, breeding and feeding grounds for fish crustaceans and other various marine biota, nutrient cycling, including many of economic importance, shoreline defense against storm surges and erosion (Donato et al., 2011;Hilmi et al., 2017;Satyanarayana et al., 2017;Dahdouh-Guebas et al., 2021). Mangroves also frequently underpin the livelihoods of local communities through their provision of timber and non-timber forest products including food (fish, crabs, and prawns), firewood, timber, waxes, honey and charcoal (Ron and Padilla, 1999;Walters et al., 2008;Zu Ermgassen et al., 2020). ...
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Global warming is characterized by high concentrations of greenhouse gas emissions, namely CO2, in the atmosphere. Mangrove ecosystems play a role in mitigating global climate change because they can absorb carbon through photosynthesis and then store it in a carbon pool, which includes Above Ground Biomass (AGB), Below Ground Biomass (BGB), litter or dead wood, and sediment. This study aimed to determine the value of biomass, carbon stocks, and CO2 sequestration in the mangrove ecosystem in the Riau Island. Carbon stocks were estimated by collecting data on AGB, BGB, and dead wood using the non-destructive allometric modeling method, and sediment sampling was carried out at 30 cm intervals until the discovery of humus soil. There are eight research stations spread across Riau Island. The results of the biomass calculation are then converted into carbon stock values and CO2 sequestration. The result showed that the mangrove ecosystem in Riau Island had a biomass value of 1854,54 tons/ha, estimated carbon stocks of 2052,78 tonsC/ha, and a CO2 sequestration of 7527,52 tonsC/ha. The mangrove ecosystem in Riau Island has an area of 79.228,91 Ha so it can store carbon reserves of 162.639.342 tonsC. The amount of CO2 can be minimized or controlled by reducing emissions and conserving forests, namely by improving mangrove management according to the function of mangrove forests.
Conference Paper
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Poverty is the condition which a person or community is being not able to fulfill basic needs in various dimension of life. Papua is a province that located in the east of Indonesia and has a high level of poverty. Eradicating poverty needs a right policy from the government and therefore proper data analysis is required in order to apply those policies. This study aims to analyze whether the relationship between poverty and location of each region exists using spatial analysis. 5 independent variables are used in the spatial regression: Regional Gross Domestic Product, Literacy Rate, School Attendance, Access to Clean Water and The Labor Force Participation Rate. The dependent variable is the percentage of poverty. First, we are processing the data to obtain The Moran Index to know if spatial autocorrelation exist. The next step is modelling the data using Spatial Autoregressive Model (SAR), Spatial Error Model (SAM) or General Spatial Model. The fit model for the data is Spatial Autoregressive Model (SAR). The significant independent variable to the model are Regional Gross Domestic Product, Literacy Rate, Access to Clean Water and The Labor Force Participation Rate. As one of three component of FGT (The Foster-Greer-Thorbecke Index), the Percentage of Poverty (P0) then calculated with Imbalance Poverty Index (P1) to generate the estimation of government funds’ allocation in alleviating poverty program.
Conference Paper
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Mangroves not only function as carbon sinks but also as food sources, wildlife habitats, and coastal protection. However, behind the enormous benefits, the information and data are still relatively minimal. In the context of the mangrove restoration and rehabilitation program in Indonesia, it is necessary to study the progress that has been achieved so far. One of the indicators assessed is the estimation of mangrove density in an area over a certain period. This study will calculate the density of mangroves in Riau Province, one of 9 priority provinces, using Sentinel 2 satellite data for 2016 and 2021. Estimation of mangrove density is carried out using vegetation indices approach, namely Modified Soil-Adjusted Vegetation Index-2 (MSAVI2), Soil-Adjusted Vegetation Index 2 (SAVI2), and Green Normalized Difference Vegetation Index-2 (GNDVI2). This vegetation index is an empirical mathematical model algorithm of the reflection of electromagnetic, visible, and near-infrared (NIR) waves. From the results of this study, the mangrove restoration and rehabilitation program in Riau Province is going as expected, and it can be seen from the change in the density level. The algorithm shows that the change in mangrove density in 2021 is about 20% for the very dense type compared to 2016.
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Mangrove ecosystems are threatened by climate change. We review the state of knowledge of mangrove vulnerability and responses to predicted climate change and consider adaptation options. Based on available evidence, of all the climate change outcomes, relative sea-level rise may be the greatest threat to mangroves. Most mangrove sediment surface elevations are not keeping pace with sea-level rise, although longer term studies from a larger number of regions are needed. Rising sea-level will have the greatest impact on mangroves experiencing net lowering in sediment elevation, where there is limited area for landward migration. The Pacific Islands mangroves have been demonstrated to be at high risk of substantial reductions. There is less certainty over other climate change outcomes and mangrove responses. More research is needed on assessment methods and standard indicators of change in response to effects from climate change, while regional monitoring networks are needed to observe these responses to enable educated adaptation. Adaptation measures can offset anticipated mangrove losses and improve resistance and resilience to climate change. Coastal planning can adapt to facilitate mangrove migration with sea-level rise. Management of activities within the catchment that affect long-term trends in the mangrove sediment elevation, better management of other stressors on mangroves, rehabilitation of degraded mangrove areas, and increases in systems of strategically designed protected area networks that include mangroves and functionally linked ecosystems through representation, replication and refugia, are additional adaptation options.
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Mangroves, the only woody halophytes living at the confluence of land and sea, have been heavily used traditionally for food, timber, fuel and medicine, and presently occupy about 181 000 km2 of tropical and subtropical coastline. Over the past 50 years, approximately one-third of the world's mangrove forests have been lost, but most data show very variable loss rates and there is considerable margin of error in most estimates. Mangroves are a valuable ecological and economic resource, being important nursery grounds and breeding sites for birds, fish, crustaceans, shellfish, reptiles and mammals; a renewable source of wood; accumulation sites for sediment, contaminants, carbon and nutrients; and offer protection against coastal erosion. The destruction of mangroves is usually positively related to human population density. Major reasons for destruction are urban development, aquaculture, mining and overexploitation for timber, fish, crustaceans and shellfish. Over the next 25 years, unrestricted clear felling, aquaculture, and overexploitation of fisheries will be the greatest threats, with lesser problems being alteration of hydrology, pollution and global warming. Loss of biodiversity is, and will continue to be, a severe problem as even pristine mangroves are species-poor compared with other tropical ecosystems. The future is not entirely bleak. The number of rehabilitation and restoration projects is increasing worldwide with some countries showing increases in mangrove area. The intensity of coastal aquaculture appears to have levelled off in some parts of the world. Some commercial projects and economic models indicate that mangroves can be used as a sustainable resource, especially for wood. The brightest note is that the rate of population growth is projected to slow during the next 50 years, with a gradual decline thereafter to the end of the century. Mangrove forests will continue to be exploited at current rates to 2025, unless they are seen as a valuable resource to be managed on a sustainable basis. After 2025, the future of mangroves will depend on technological and ecological advances in multi-species silviculture, genetics, and forestry modelling, but the greatest hope for their future is for a reduction in human population growth.
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1] Wetlands represent the largest component of the terrestrial biological carbon pool and thus play an important role in global carbon cycles. Most global carbon budgets, however, have focused on dry land ecosystems that extend over large areas and have not accounted for the many small, scattered carbon-storing ecosystems such as tidal saline wetlands. We compiled data for 154 sites in mangroves and salt marshes from the western and eastern Atlantic and Pacific coasts, as well as the Indian Ocean, Mediterranean Ocean, and Gulf of Mexico. The set of sites spans a latitudinal range from 22.4°S in the Indian Ocean to 55.5°N in the northeastern Atlantic. The average soil carbon density of mangrove swamps (0.055 ± 0.004 g cm À3) is significantly higher than the salt marsh average (0.039 ± 0.003 g cm À3). Soil carbon density in mangrove swamps and Spartina patens marshes declines with increasing average annual temperature, probably due to increased decay rates at higher temperatures. In contrast, carbon sequestration rates were not significantly different between mangrove swamps and salt marshes. Variability in sediment accumulation rates within marshes is a major control of carbon sequestration rates masking any relationship with climatic parameters. Globally, these combined wetlands store at least 44.6 Tg C yr À1 and probably more, as detailed areal inventories are not available for salt marshes in China and South America. Much attention has been given to the role of freshwater wetlands, particularly northern peatlands, as carbon sinks. In contrast to peatlands, salt marshes and mangroves release negligible amounts of greenhouse gases and store more carbon per unit area.
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Aim Our scientific understanding of the extent and distribution of mangrove forests of the world is inadequate. The available global mangrove databases, compiled using disparate geospatial data sources and national statistics, need to be improved. Here, we mapped the status and distributions of global mangroves using recently available Global Land Survey (GLS) data and the Landsat archive. Methods We interpreted approximately 1000 Landsat scenes using hybrid supervised and unsupervised digital image classification techniques. Each image was normalized for variation in solar angle and earth–sun distance by converting the digital number values to the top-of-the-atmosphere reflectance. Ground truth data and existing maps and databases were used to select training samples and also for iterative labelling. Results were validated using existing GIS data and the published literature to map ‘true mangroves’. Results The total area of mangroves in the year 2000 was 137,760 km2 in 118 countries and territories in the tropical and subtropical regions of the world. Approximately 75% of world's mangroves are found in just 15 countries, and only 6.9% are protected under the existing protected areas network (IUCN I-IV). Our study confirms earlier findings that the biogeographic distribution of mangroves is generally confined to the tropical and subtropical regions and the largest percentage of mangroves is found between 5° N and 5° S latitude. Main conclusions We report that the remaining area of mangrove forest in the world is less than previously thought. Our estimate is 12.3% smaller than the most recent estimate by the Food and Agriculture Organization (FAO) of the United Nations. We present the most comprehensive, globally consistent and highest resolution (30 m) global mangrove database ever created. We developed and used better mapping techniques and data sources and mapped mangroves with better spatial and thematic details than previous studies.
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Nearly 50% of terrigenous materials delivered to the world's oceans are delivered through just twenty-one major river systems. These river-dominated coastal margins (including estuarine and shelf ecosystems) are thus important both to the regional enhancement of productivity and to the global flux of C that is observed in land-margin ecosystems. The tropical regions of the biosphere are the most biogeochemically active coastal regions and represent potentially important sinks of C in the biosphere. Rates of net primary productivity and biomass accumulation depend on a combination of global factors such as latitude and local factors such as hydrology. The global storage of C in mangrove biomass is estimated at 4.03 Pg C; and 70% of this C occurs in coastal margins from 0 to 10 latitude. The average rate of wood production is 12.08 Mg ha–1 yr–1, which is equivalent to a global estimate of 0.16 Pg C/yr stored in mangrove biomass. Together with carbon accumulation in mangrove sediments (0.02 Pg C/yr), the net ecosystem production in mangroves is about 0.18 Pg C/yr. Global estimates of export from coastal wetlands is about 0.08 Pg C/yr compared to input of 0.36 Pg C/yr from rivers to coastal ecosystems. Total allochthonous input of 0.44 Pg C/yr is lower than in situ production of 6.65 Pg C/yr. The trophic condition of coastal ecosystems depends on the fate of this total supply of 7.09 Pg C/yr as either contributing to system respiration, or becoming permanently stored in sediments. Accumulation of carbon in coastal sediments is only 0.41 Pg C/yr; about 6% of the total input. The NEP of coastal wetlands also contribute to the C sink of coastal margins, but the source of this C is part of the terrestrial C exchange with the atmosphere. Accumulation of C in wood and sediments of coastal wetlands is 0.205 Pg C/yr, half the estimate for sequestering of C in coastal sediments. Burial of C in shelf sediments is probably underestimated, particularly in tropical river-dominated coastal margins. Better estimates of these two C sinks in the tropics, coastal wetlands and shelf sediments, is needed to better understand the contribution of coastal ecosystems to the global carbon budget.
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The coastal zone has changed profoundly during the 20th century and, as a result, society is becoming increasingly vulnerable to the impact of sea-level rise and variability. This demands improved understanding to facilitate appropriate planning to minimise potential losses. With this in mind, the World Climate Research Programme organised a workshop (held in June 2006) to document current understanding and to identify research and observations required to reduce current uncertainties associated with sea-level rise and variability. While sea levels have varied by over 120m during glacial/interglacial cycles, there has been little net rise over the past several millennia until the 19th century and early 20th century, when geological and tide-gauge data indicate an increase in the rate of sea-level rise. Recent satellite-altimeter data and tide-gauge data have indicated that sea levels are now rising at over 3mmyear−1. The major contributions to 20th and 21st century sea-level rise are thought to be a result of ocean thermal expansion and the melting of glaciers and ice caps. Ice sheets are thought to have been a minor contributor to 20th century sea-level rise, but are potentially the largest contributor in the longer term. Sea levels are currently rising at the upper limit of the projections of the Third Assessment Report of the Intergovernmental Panel on Climate Change (TAR IPCC), and there is increasing concern of potentially large ice-sheet contributions during the 21st century and beyond, particularly if greenhouse gas emissions continue unabated. A suite of ongoing satellite and in situ observational activities need to be sustained and new activities supported. To the extent that we are able to sustain these observations, research programmes utilising the resulting data should be able to significantly improve our understanding and narrow projections of future sea-level rise and variability.
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Aboveground and belowground root biomasses (Babove and Broot) were measured for young, isolated Rhizophorastylosa on Iriomote Island, Japan. The relationship between these two parameters was significant and given as the equation, Broot(g dry weight) = 0.394 Babove(g dry weight) – 485 (r = 0.986). Multiple regression analyses also revealed good correlation between diameter and biomass of prop roots (Dprop and Bprop) and between prop root and root biomasses. Consequently, root biomass could be estimated from the measurements of diameter and biomass of prop roots using the multiple regression equation, Broot(g dry weight) = 80.0 Dprop(cm) + 0.86 Bprop (g dry weight) – 251. The relationship between DBH (diameter at breast height) and prop root biomass was also adequately described using an allometric equation.In Hinchinbrook Channel, Australia, redox potential (measured as Eh) and organic carbon stocks in the top 5cm of mangrove sediments were measured along a 600m transect from the frequently inundated, Rhizophora dominated zone on the creek edge, towards higher grounds, where Ceriops spp. became increasingly dominant. Eh values were about –60mV near the creek edge and increased to 260mV on higher grounds. Organic carbon stocks showed an opposite trend to Eh, with the values decreasing from about 360tCha–1 to 160tCha–1. At 18 sites, representing six different habitats, organic carbon stocks were also measured along with the DBH of mangrove trees. DBH was converted into aboveground biomass and then into root biomass using the equations obtained in the study on Iriomote Island. The average organic carbon stocks in the top 50 cm of sediments, aboveground biomass and root biomass were 296tCha–1, 123 tCha–1 and 52 tCha–1, respectively, and accounted for 64%, 25% and 11% of the total organic carbon stock.
Accurate inventory of tropical peatland is important in order to (a) determine the magnitude of the carbon pool; (b) estimate the scale of transfers of peat-derived greenhouse gases to the atmosphere resulting from land use change; and (c) support carbon emissions reduction policies. We review available information on tropical peatland area and thickness and calculate peat volume and carbon content in order to determine their best estimates and ranges of variation. Our best estimate of tropical peatland area is 441 025 km 2 ($11% of global peatland area) of which 247 778 km 2 (56%) is in Southeast Asia. We estimate the volume of tropical peat to be 1758 Gm 3 ($ 18–25% of global peat volume) with 1359 Gm 3 in Southeast Asia (77% of all tropical peat). This new assessment reveals a larger tropical peatland carbon pool than previous estimates, with a best estimate of 88.6 Gt (range 81.7–91.9 Gt) equal to 15–19% of the global peat carbon pool. Of this, 68.5 Gt (77%) is in Southeast Asia, equal to 11–14% of global peat carbon. A single country, Indonesia, has the largest share of tropical peat carbon (57.4 Gt, 65%), followed by Malaysia (9.1 Gt, 10%). These data are used to provide revised estimates for Indonesian and Malaysian forest soil carbon pools of 77 and 15 Gt, respectively, and total forest carbon pools (biomass plus soil) of 97 and 19 Gt. Peat carbon contributes 60% to the total forest soil carbon pool in Malaysia and 74% in Indonesia. These results emphasize the prominent global and regional roles played by the tropical peat carbon pool and the importance of including this pool in national and regional assessments of terrestrial carbon stocks and the prediction of peat-derived greenhouse gas emissions.